The present invention relates to a device for forming and strapping or banding groups of sheets, banknotes in particular.
The invention finds application to advantage in machines by which banknotes are ordered and wrapped in bundles; indeed reference is made directly to this same art field in the following specification, albeit with no limitation in scope implied.
The fitness of banknotes for continued use can be verified utilizing machines, embraced by the prior art, comprising a plurality of stacking modules with respective formation channels. Banknotes of whatever type are fed singly and in succession into the modules, examined and rejected if defective, then sorted according to denomination and/or type and directed separately toward respective outlets afforded by the channels. In this way, stacks of single banknotes are formed at each of the outlets.
As the single notes are accumulated and grouped in predetermined numbers, each stack is collected from the outlet of the relative channel by a pickup and transfer device and distanced from the channel. The pickup and transfer device is capable typically of movement along a predetermined path extending along the machine and able thus to address each one of the channels whenever a group of banknotes has formed at the relative outlet, so that the notes can be taken up and transferred to a strapping or banding station.
On arrival at the station in question, the group of notes is released to a pickup device operating in conjunction with a strapper/bander device by which at least one wrapping band is fastened around the group to produce a respective bundle.
Whilst the machines in question lack nothing in terms of the effectiveness and precision with which the operation of strapping or banding the groups of banknotes is carried out, they betray the drawback that each group of banknotes accumulated has to be transferred in turn from the respective formation channel to the strapping/banding station, which in most machines will occupy a position remote from the stacking module.
This means that the pickup and transfer devices must be capable of high operating speeds in order to match the rapid rates at which the groups of notes are formed cyclically along the respective channels making up the machine.
Accordingly, the devices in question need to be equipped with efficient and reliable means by which to pick up and retain the stacks of banknotes in order to ensure a correct transfer with no tendency of the stack to break up, also with sophisticated tracking systems able to ensure high positioning accuracy, which is often difficult to obtain given the high operating speeds demanded. The effect of such requirements is obviously to incur additional costs impacting significantly on the cost of the machine overall.
The problem is especially evident when used notes are being processed, by reason of the difficulty in handling and compacting such notes when stacked.
Notwithstanding the constraints imposed by the fact that the groups of notes must be transferred without breaking up, and the need for a high level of accuracy in positioning, it has been possible in practice to obtain high operating speeds from the pickup transfer devices, albeit such speeds always remain low in relation to the rates at which the notes are stacked into groups along the formation channels, and in consequence the production cycle of the machine overall continues to be slowed down; thus, there is no material advantage ultimately in the fact that notes can be processed and stacked efficiently and swiftly by such machines.
The object of the present invention is to provide a device for the formation and strapping or banding of groups of banknotes such as will increase the productivity of the currency processing machines in question, simplifying and speeding up the step of picking up the bundles and overcoming the drawbacks described above.